On the way home from work today, on the highway, the amber engine light on the center speedo (2008 S) came on, and my wife pulled over and called the two truck. She said it was running rough.

When they unloaded the car from the ramp truck at home, the tech stuck the key in, and the headlights were really dim. He took their jumper battery and connected it, and the car started!

He backed it on down and left the car in in the driveway. Unfortunately, the car was sitting in front of the one I needed to drive to work, so I tried to put the Mini in neutral. No go. I had to get another car with jumpers, and jump the car, so it would go in neutral. Automatic tranny, if that wasn't clear. Fearing the steering would lock, I left the key in the ignition. As I was pushing it back, things were flashing like a bad horror movie.

After I pushed the Mini back, I parked my other car and came back to the driveway. And the windows were down in the Mini. WTF? And there wasn't any juice to roll them up.

I got the other car and the jumper cables again, and raised the passenger window. The drivers would only go up a bit at a time when the switch was pushed, but I finally got the window into a position the door would close.

Jumping with my measly cables wouldn't even begin to get the car enough juice to start.

If you're still reading this, here's finally my question: Is it likely a battery would just die on the road? I'm not saying its' impossible, I've just never heard of it happening.

 

Could be battery, how old is it? Could also be a dead alternator. Serpentine belt OK? How old is it?
Model, year and total miles are good to share also.

 

Yes, if alternator is going out it'll cause the battery to die beacause you're using power and not being able to read charge the battery. How old is battery? Also testing to see if the alternator is going out is simple.

 

I have seen batteries fail while driving. Internally shorted. I would maybe have the battery charged and tested, but if it's over 3 years old, best bet is battery. If the battery is bad/shorted internally, even checking voltage while running may show low voltage/low alternator output.

 

If the car turned off while driving, i suspect the alternator dead. If you can start the car and while car is running, remove the batt negative connection and see if remains running.
It is normal for the windows to behaive like this specially while the door is open.

 

1) Bad alternator
2) Too old battery
3) Something in your wiring/devices/lights eating your battery due a problem
4) Combination of some of them (I hope it is not your case).

 

I thought I'd also suggested the possibility of a loose or corroded cable connection. Guess not. That's another place to look.

 

+1 bad alternator that drained that battery, whats happens is that you are driving along, then all the lights on the dash come on, then things stop working, then CEL comes on and then the radio does not come on...etc

Check the battery first though, then the alternator. Its the easiest to replace.

 

I have to disagree with that advice. Disconnecting the battery while running is liable to cause a voltage spike damaging your electronics. You can easily check if you are charging with a DMM

 

That was a naration of my experience. I did it few times and nothing happened on my end.

We share experiences. It is upto the individual to take it or not!

 

thanks for the replies! Here's the latest: Took the battery to the local parts store. They charged it (it was at 2%), and said it was ok.

I put the battery in, and started the car. It was running rough, and the yellow engine icon is on in the center console (2008 S if I hadn't said that already). There is also an icon for the car on a lift showing in front of the driver.

My wife mentioned the car running rough when it quit on the highway.

I hooked up my code reader..and nothing. No codes.

I'll take it to the parts store for an alternator check, and maybe they can read the codes. But I'm not getting anything.

Any ideas? It feels like a bad coil, but you normally get a misfire code. And I'm not sure that's a symptom, a cause, or just incidental to what happened.

 

I forgot to mention that I checked the ground strap to the motor, at the passenger side. It's in good condition.

 

car battery charge is not normally measured in percentage so its hard to interpret what that means. get yourself a cheap dmm and measure voltage. off normaly 12.5+, low 12's is discharged, below 11.5 probably permanently damaged. when running it should immediately come up over 13v

 

I have had 2 batteries fail internally, one pre MINI, one on my 2012 MINI. Batteries that fail can fail such that the voltage continues to read about 12+ volts but unable to generate any amperage. In a MINI, Low voltage really confuses the various computers. Remember, everything in a MINI is computer controlled. When my MINI's battery failed the CD player could by heard spinning up / spinning down over and over. odd.

 

If you battery is more than 3 years old I'd buy a new one & go from there. My guess is a dead battery. Even if it turns out to be the alternator I wouldn't feel bad replacing an old battery with a new one.

 

You could go to the parts store again to charge the battery.
If is low on charge again, change the battery for a new one.
If the new battery get low on charge, then surely the alternator is the problem.
After all you will have new battery running with a working alternator.

 

I left the recharged battery in the car for a couple of days without driving it, in weather that dipped down to about 10F at night. Got into it yesterday and it started right up. I still have the "check engine" light on that doesn't get any codes, so I guess I'll have to take it to a German car service place and have them look at it. I did go and buy a new battery. However...

Three items of interest that maybe someone could help me with:

1) the window dipper doesn't work. My wife said it hasn't in awhile.

2) She also said it used to make a "ding" noise when you got in the car but now doesn't

3) I noticed the CD player keeps trying to eject a CD, but there is no CD in the radio, and never has been. It stops doing this after a few minutes, but it's odd.

I have to wonder if there is a parasitic draw of some kind. I'll try and reset the window, but I'm concerned a bad window motor killed the battery. I'll see if I can borrow someone's DVM and check for a drain. I need to figure this out, as my wife refuses to drive the car, and I can't blame her.

 

Have you replaced the battery with a new one yet as suggested above ?

Also, when a battery is replaced in the R56 models at the dealer, it is registered to the car with the BMW computer which also sends a message to the DME to " adjust charging cycles for a period time, new battery installed."

 

I think having to register the battery was only with certain optional equipment (can't remember the acronym right now- IBS?) Anyways, went to the parts store today and had them run battery check and charging check. Everything came back fine.
Did the 10 second up/down thing with the window switch, and restored the window dipping function. The CD player wasn't doing the eject thing this afternoon.

At this point I'm going to chalk all this strangeness up to a bad battery, and move on to other problems (water pump)

 

A final word on this. The car was running fine, then bad, then really bad. Final result was the car ingested a spark plug, with significant damage. [sigh]

 

it happened to me once already...i bought a block and a head and moved the good parts and replaced the bad ones. it can be done